Ophthalmic implants with extended depth of field and enhanced distance visual acuity

ABSTRACT

A lens configured for implantation into an eye of a human can include an optic including transparent material. The optic can have an anterior surface and a posterior surface. The anterior surface can be convex and the posterior surface can be concave such that the optic is meniscus shaped. Each of the convex anterior surface and the concave posterior surface can have a surface vertex. The optic can have an optical axis through the surface vertices and a thickness along the optical axis that is between about 100-700 micrometers. The lens can also include haptic portions disposed about the optic to affix the optic in the eye when implanted therein. The anterior and posterior surfaces can include aspheric surfaces.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/848,082 filed Sep. 8, 2015, which claims the benefit of priority ofU.S. Provisional Application No. 62/048,135, U.S. ProvisionalApplication No. 62/048,705, and U.S. Provisional Application No.62/149,481 filed respectively on Sep. 9, 2014, Sep. 10, 2014, and Apr.17, 2015. The entire disclosures of each of the prior applications arehereby expressly incorporated by reference.

BACKGROUND Field of the Invention

This disclosure relates to ophthalmic implants, for example, toophthalmic implants with extended depth of field.

Description of the Related Art

FIG. 1 is a schematic illustration of the human eye. As shown in FIG. 1,the human eye 100 includes a cornea 110, an iris 115, a naturalcrystalline lens 120, and a retina 130. Light enters the eye 100 throughthe cornea 110 and towards the pupil, which is the opening in the centerof the iris 115. The iris 115 and pupil help regulate the amount oflight entering the eye 100. In bright lighting conditions, the iris 115closes the pupil to let in less light, while in dark lightingconditions, the iris 115 opens the pupil to let in more light. Posteriorto the iris 115 is a natural crystalline lens 120. The cornea 110 andthe crystalline lens 120 refract and focus the light toward the retina130. In an eye 100 with a visual acuity of 20/20, the crystalline lens120 focuses the light to the back of the eye onto the retina 130. Theretina 130 senses the light and produces electrical impulses, which aresent through the optic nerve 140 to the brain. When the eye does notproperly focus the light, corrective and/or artificial lenses have beenused.

SUMMARY

Certain embodiments described herein include a lens configured forimplantation into an eye of a human. The lens can include an opticcomprising transparent material. The lens can also include hapticportions disposed about the optic to affix the optic in the eye whenimplanted therein. The optic can include an anterior surface and aposterior surface. The anterior surface can be convex and the posteriorsurface can be concave such that the optic is meniscus shaped. Each ofthe convex anterior surface and the concave posterior surface can have asurface vertex. The optic can have an optical axis through the surfacevertices. In various embodiments, a thickness along the optical axis canbe between about 100-700 micrometers (or any range formed by any of thevalues in this range). In addition, the anterior and posterior surfacescan comprise aspheric surfaces.

Certain embodiments described herein include a lens configured forimplantation into an eye of a human. The lens can include an opticcomprising transparent material. The lens can also include at least onehaptic disposed with respect to the optic to affix the optic in the eyewhen implanted therein. The optic can have an anterior surface and aposterior surface. The anterior surface can be convex and the posteriorsurface can be concave such that the optic is meniscus shaped. Each ofthe convex anterior surface and the concave posterior surface can have asurface vertex. The optic can have an optical axis through the surfacevertices. In various embodiments, the anterior and posterior surfacescan comprise aspheric surfaces. The anterior surface can have anaspheric shape that comprises a conic or biconic offset by perturbationscomprising an aspheric higher order function of radial distance from theoptical axis.

In some such embodiments, the aspheric higher order function can includeat least one even order term, a_(2n)r^(2n), where n is an integer anda_(2n) is a coefficient and r is the radial distance from the opticalaxis. For example, the aspheric higher order function can include asecond order term, a₂r², where a₂ is a coefficient and r is the radialdistance from the optical axis. As another example, the aspheric higherorder function can include a fourth order term, a₄r⁴, where a₄ is acoefficient and r is the radial distance from the optical axis. Theaspheric higher order function also can include a sixth order term, a₆r⁶where a₆ is a coefficient and r is the radial distance from the opticalaxis. Furthermore, the aspheric higher order function can include aneighth order term, a₈r⁸ where a₈ is a coefficient and r is the radialdistance from the optical axis. In some embodiments of the lens, theoptic can have a thickness along the optical axis that is between about100-700 microns (or any range formed by any of the values in thisrange). In various embodiments, the anterior surface has an asphericshape that comprises a biconic offset by the perturbations.

Certain embodiments described herein include a lens configured forimplantation into an eye of a human. The lens can include an opticcomprising transparent material. The lens can also include at least onehaptic disposed with respect to the optic in the eye when implantedtherein. The optic can have an anterior surface and a posterior surface.The anterior surface can be convex and the posterior surface can beconcave such that the optic is meniscus shaped. Each of the convexanterior surface and the concave posterior surface can have a surfacevertex. The optic can have an optical axis through the surface vertices.In various embodiments, the anterior and posterior surfaces can compriseaspheric surfaces. The posterior surface can have an aspheric shape thatcomprises a conic or biconic offset by perturbations comprising anaspheric higher order function of radial distance from the optical axis.In various embodiments, the posterior surface has an aspheric shape thatcomprises a biconic offset by the perturbations.

Certain embodiments described herein include a lens configured forimplantation into an eye of a human. The lens can include an opticcomprising transparent material. The optic can have an anterior surfaceand a posterior surface. The anterior surface can comprise an asphericsurface. The anterior and posterior surfaces also can be shaped toprovide average modulation transfer function (MTF) values that arebetween 0.1 and 0.4 at 100 lines per millimeter for at least 90% of theobject vergences within the range of 0 to 2.5 Diopter (D) when the opticis inserted into the human eye having an aperture size of aperture sizeof 2 to 6 millimeters, 3 to 6 millimeters, or 4 to 6 millimeters (e.g.,the aperture size can be 2 mm, 3 mm, 4 mm, 6 mm, any value within theseranges, or any range formed by such values). The average MTF values cancomprise MTF values at 100 lines per millimeter integrated over thewavelengths between about 400 to 700 nm weighted by the photopicluminosity function for on axis objects.

In various embodiments, the human eye comprises a crystalline lens andthe average modulation transfer function values are provided when theoptic is inserted anterior of the crystalline lens. In various otherembodiments, the human eye excludes a crystalline lens and themodulation transfer function values are provided when the optic isinserted in place of the crystalline lens. The lens further can comprisehaptic portions. In addition, the optic can have an optical axis and athickness through the optical axis that is between about 100-700 microns(or any range formed by any of the values in this range).

Certain embodiments described herein include a lens configured forimplantation into an eye of a human. The lens can include an opticcomprising transparent material. The optic can have an anterior surfaceand a posterior surface. The anterior surface can comprise an asphericsurface. The anterior and posterior surfaces also can be shaped toprovide average modulation transfer function (MTF) values that arebetween 0.1 and 0.4 at 100 lines per millimeter for at least 90% of theobject vergences within the range of 0 to 2.5 Diopter (D) when the opticis inserted into a model eye having an aperture size of 2 to 6millimeters, 3 to 6 millimeters, or 4 to 6 millimeters (e.g., theaperture size can be 2 mm, 3 mm, 4 mm, 6 mm, any value within theseranges, or any range formed by such values). The average MTF values cancomprise MTF values at 100 lines per millimeter integrated over thewavelengths between about 400 to 700 nm weighted by the photopicluminosity function for on axis objects.

The model eye can comprise a Liou-Brennan model eye. Alternatively, themodel eye can comprise a Badal model eye. Furthermore, the model eye cancomprise an Arizona model eye or an Indiana model eye. Otherstandardized or equivalent model eyes can be used.

In some embodiments, the modulation transfer function values can beprovided when the optic is inserted in the model eye in a phakicconfiguration. In some other embodiments, the modulation transferfunction values can be provided when the optic is inserted in the modeleye in an aphakic configuration. The lens can further comprise hapticportions. Furthermore, the optic can have an optical axis and athickness through the optical axis that is between about 100-700 microns(or any range formed by any of the values in this range).

Certain embodiments described herein include a lens configured forimplantation into an eye of a human. The lens can include an opticcomprising transparent material. The optic can have an anterior surfaceand a posterior surface and an exit pupil. The anterior surface cancomprise an aspheric surface. The anterior and posterior surfaces can beshaped to provide a radial power profile characterized byΦ(r)=a+br²+cr⁴+dr⁶+er⁸ for wavefront at the exit pupil of the optic foran object vergence of 0 to 2.5 Diopter (D) where r is the radialdistance from an optical axis extending through the surface vertices onthe anterior and posterior surfaces and a, b, c, d, and e arecoefficients.

Certain embodiments described herein include a lens configured forimplantation into an eye of a human. The lens can include an opticcomprising transparent material. The lens can also include at least onehaptic disposed with respect to the optic to affix the optic in the eyewhen implanted therein. The optic can include an anterior surface and aposterior surface. Each of the anterior surface and the posteriorsurface can have a surface vertex. The optic can have an optical axisthrough the surface vertices. The thickness along the optical axis canbe between about 100-400 micrometers (or any range formed by any of thevalues in this range). In addition, at least one of the anterior andposterior surfaces can comprise aspheric surfaces. In some embodiments,the anterior surface can be convex. In addition, the posterior surfacecan be concave.

Certain embodiments described herein include a lens configured forimplantation into an eye of a human. The lens can include an opticcomprising transparent material. The lens can also include at least onehaptic disposed with respect to the optic to affix the optic in the eyewhen implanted therein. The optic can include an anterior surface and aposterior surface. Each of the anterior surface and the posteriorsurface can have a surface vertex. The optic can have an optical axisthrough the surface vertices. At least one of the anterior and posteriorsurfaces can comprise an aspheric surface including perturbationscomprising an aspheric higher order function of radial distance from theoptical axis and at least one of the surfaces can have an aspheric shapethat comprises a biconic. In some embodiments, the anterior surface canbe convex. In addition, the posterior surface can be concave.

Certain embodiments described herein include a lens configured forimplantation into an eye of a human. The lens can include an opticcomprising transparent material. The lens can also include hapticportions disposed about the optic to affix the optic in the eye whenimplanted therein. The optic can include an anterior surface and aposterior surface. Each of the anterior surface and the posteriorsurface can have a surface vertex. The optic can have an optical axisthrough the surface vertices. The thickness along the optical axis canbe between about 100-700 micrometers (or any range formed by any of thevalues in this range). In addition, the anterior and posterior surfacescan comprise aspheric surfaces.

Certain embodiments described herein include a lens configured forimplantation into an eye of a human. The lens can include an opticcomprising transparent material. The lens can also include at least onehaptic disposed with respect to the optic to affix the optic in the eyewhen implanted therein. The optic can include an anterior surface and aposterior surface. Each of the anterior surface and the posteriorsurface can have a surface vertex. The optic can have an optical axisthrough the surface vertices. At least one of the anterior and posteriorsurfaces can comprise an aspheric surface that comprises a conic orbiconic offset by perturbations comprising an aspheric higher orderfunction of radial distance from the optical axis.

In various embodiments of the lens described herein comprising atransparent material, the transparent material can comprise collamer.The transparent can comprise silicone, acrylics, or hydrogels. Thetransparent material can comprise hydrophobic or hydrophilic material.

In various embodiments of the lens described herein, the anteriorsurface can be rotationally symmetric. The anterior surface can have ashape that includes a conic or biconic term. The anterior surface canhave a shape that includes a conic or biconic term and aspheric higherorder perturbation terms. In some embodiments of the lens, the posteriorsurface can have a shape that includes a conic or biconic term. Theconic or biconic term can have a conic constant having a magnitudegreater than zero. For example, the conic or biconic term can have aconic constant having a magnitude of at least one. As another example,the conic or biconic term can have a conic constant having a magnitudeof at least ten.

In various embodiments of the lens described herein, the posteriorsurface can be rotationally non-symmetric. The posterior surface canhave different curvature along different directions through the opticalaxis of the optic. For example, the posterior surface can have differentcurvature along orthogonal directions through the optical axis of theoptic. The shape of the posterior surface can include a biconic term.The biconic term can have a conic constant having a magnitude greaterthan zero. For example, the biconic term can have a conic constanthaving a magnitude of at least one. As another example, the conic orbiconic term can have a conic constant having a magnitude of at leastten. In various embodiments of the lens described herein, the optic canhave a thickness along the optical axis of between 100-400 micrometers.For example, the thickness along the optical axis can be between 100-300micrometers, between 100-200 micrometers, between 200-300 micrometers,between 300-400 micrometers, or any range formed by any of the values inthese ranges.

In various embodiments of the lens described herein, the anterior andposterior surfaces of the lens can be shaped to provide averagemodulation transfer function (MTF) values that are between 0.1 and 0.4at 100 lines per millimeter for at least 90% of the object vergenceswithin the range of 0 to 2.5 Diopter (D) when the optic is inserted intoa model eye having an aperture size of 2 to 6 millimeters, 3 to 6millimeters, or 4 to 6 millimeters (e.g., the aperture size can be 2 mm,3 mm, 4 mm, 6 mm, any value within these ranges, or any range formed bysuch values). The average MTF values can comprise MTF values at 100lines per millimeter integrated over the wavelengths between about 400to 700 nm weighted by the photopic luminosity function for on axisobjects. The model eye can comprise a Liou-Brennan model eye, a Badalmodel eye, an Arizona model eye, an Indiana model eye, or anystandardized or equivalent model eye.

In some such embodiments, the anterior and posterior surfaces of thelens are shaped to provide average modulation transfer function (MTF)values that are between 0.1 and 0.4 at 100 lines per millimeter for atleast 95% or 98% of the object vergences within the range of 0 to 2.5Diopter (D).

In various embodiments of the lens described herein, the anterior andposterior surfaces can be shaped to provide modulation transferfunctions (MTF) without phase reversal for at least 90% of the objectvergences within the range of 0 to 2.5 Diopter (D) when the optic isinserted into the model eye. In some such embodiments, the anterior andposterior surfaces are shaped to provide modulation transfer functions(MTF) without phase reversal for at least 95%, 98%, 99%, or 100% of theobject vergences within the range of 0 to 2.5 Diopter (D) when saidoptic is inserted into the model eye.

In various embodiments of the lens described herein, the anteriorsurface can have a radius of curvature between 0 to 1 mm, between 1×10⁻⁶to 1×10⁻³ mm, or between 5×10⁻⁶ to 5×10⁻⁴ mm. The anterior surface canhave a conic constant between −1×10⁶ to −100 or between −3×10⁵ to−2×10⁵. The posterior surface can have a radius of curvature, R_(y),between 0 to 20 mm. The posterior surface can have a radius ofcurvature, R_(x), between 0 to 20 mm. The posterior surface can have aconic constant, k_(y) between −20 to 20 mm. The posterior surface canhave a conic constant, k_(x), between −25 to 0 mm.

In some embodiments of the lens described herein, the lens can beconfigured to be disposed anterior to the natural lens of the eye. Insome other embodiments of the lens, the lens can be configured to bedisposed in the capsular bag.

Certain embodiments described herein include a method of implanting thelens of any of the embodiments of the lens. The method can includeforming an opening in tissue of the eye and inserting the lens anteriorof the natural lens of the eye. Certain embodiments described hereinalso include a method including forming an opening in tissue of the eyeand inserting the lens in the capsular bag.

In various embodiments of the lens described herein, the optic can havea thickness along the optical axis that is between about 700 microns-4millimeter. For example, the thickness along the optical axis can bebetween about 700 microns-3 millimeter, between about 700 microns-2millimeter, between about 700 microns-1 millimeter, or any range formedby any of the values in these ranges.

Certain embodiments described herein include a lens pair configured forimplantation into a pair of left and right eyes of a human. The lenspair includes a first lens. The first lens can include an opticcomprising transparent material. The optic of the first lens can have ananterior surface and a posterior surface. The anterior surface caninclude an aspheric surface. The anterior and posterior surfaces of thefirst lens can be shaped to provide average modulation transfer function(MTF) values that are between 0.1 and 0.4 at 100 lines per millimeterfor at least 90% of the object vergences within the range of 0 to 2.0Diopter or 0 to 2.5 Diopter (D) when the optic of the first lens isinserted into a model eye having an aperture size of 2 to 6 millimeters,3 to 6 millimeters, or 4 to 6 millimeters (e.g., the aperture size canbe 2 mm, 3 mm, 4 mm, 6 mm, any value within these ranges, or any rangeformed by such values). The average MTF values of the first lens cancomprise MTF values at 100 lines per millimeter integrated over thewavelengths between about 400 to 700 nm weighted by the photopicluminosity function for on axis objects.

The lens pair also includes a second lens. The second lens can includean optic comprising transparent material. The optic of the second lenscan have an anterior surface and a posterior surface. The anteriorsurface can include an aspheric surface. The anterior and posteriorsurfaces of the second lens can be shaped to provide average modulationtransfer function (MTF) values that are between 0.1 and 0.4 at 100 linesper millimeter for at least 90% of the object vergences within the rangeof −2.0 to 0 Diopter or −2.5 to 0 Diopter (D) when the optic of thesecond lens is inserted into a model eye having an aperture size of 2 to6 millimeters, 3 to 6 millimeters, or 4 to 6 millimeters (e.g., theaperture size can be 2 mm, 3 mm, 4 mm, 6 mm, any value within theseranges, or any range formed by such values). The average MTF values ofthe second lens can comprise MTF values at 100 lines per millimeterintegrated over the wavelengths between about 400 to 700 nm weighted bythe photopic luminosity function for on axis objects.

The model eye can comprise a Liou-Brennan model eye. Alternatively, themodel eye can comprise a Badal model eye. Furthermore, the model eye cancomprise an Arizona model eye or an Indiana model eye. Otherstandardized or equivalent model eyes can be used.

In various embodiments of the lens pair, the modulation transferfunction values of the first or second lens can be provided when theoptic of the first or second lens is inserted in the model eye in aphakic configuration. In various other embodiments, the modulationtransfer function values of the first or second lens can be providedwhen the optic of the first or second lens is inserted in the model eyein an aphakic configuration.

In various embodiments of the lens pair, the first or second lens canfurther comprise haptic portions. The optic of the first or second lenscan have an optical axis and a thickness through the optical axis thatis between about 100-700 microns. In other embodiments, the optic of thefirst or second lens can have an optical axis and a thickness throughthe optical axis that is between about 700 microns-4 millimeter. In somesuch embodiments, the thickness along the optical axis can be betweenabout 700 microns-3 millimeter, between about 700 microns-2 millimeter,between about 700 microns-1 millimeter, or any range formed by any ofthe values in these ranges.

In various embodiments of the lens pair, the anterior and posteriorsurfaces of the first lens can be shaped to provide average modulationtransfer function (MTF) values that are between 0.1 and 0.4 at 100 linesper millimeter for at least 95% or 98% of the object vergences withinthe range of 0 to 2.5 Diopter (D).

In various embodiments of the lens pair, the anterior and posteriorsurfaces of the second lens can be shaped to provide average modulationtransfer function (MTF) values that are between 0.1 and 0.4 at 100 linesper millimeter for at least 95% or 98% of the object vergences withinthe range of −2.5 to 0 Diopter (D).

In various embodiments of the lens pair, the anterior and posteriorsurfaces of the first lens can shaped to provide modulation transferfunctions (MTF) without phase reversal for at least 90%, 95%, 98%, 99%,or 100% of the object vergences within the range of 0 to 2.5 Diopter (D)when said optic is inserted into the model eye.

In various embodiments of the lens pair, the anterior and posteriorsurfaces of the second lens can be shaped to provide modulation transferfunctions (MTF) without phase reversal for at least 90%, 95%, 98%, 99%,or 100% of the object vergences within the range of −2.5 to 0 Diopter(D) when said optic is inserted into the model eye.

Certain embodiments described herein include a lens configured forimplantation into an eye of a human. The lens can include an opticcomprising transparent material. The optic can have an anterior surfaceand a posterior surface. Each of the anterior surface and the posteriorsurface can have a surface vertex. The optic can have an optical axisthrough the surface vertices. At least one of the anterior and posteriorsurfaces can comprise a surface having a first portion and a secondportion. The first portion can be disposed centrally about the opticalaxis. The second portion can surround the first portion and can have adifferent surface profile than the first portion. The first portion canbe configured to provide an extended depth of field. The second portioncan be configured to provide an enhanced vision quality metric atdistance in comparison to the first portion.

In some such embodiments, distance can comprise objects between infinityto 2 meters or distance can comprises 0 D vergence. In variousembodiments of the lens, the lens can further comprise a third portionsurrounding the second portion. The third portion can have a differentsurface profile than the second portion. In some embodiments, the thirdportion can have a similar surface profile as the first portion. Thesecond portion can be configured to provide an enhanced vision qualitymetric at distance in comparison to the third portion. For example, theenhanced vision quality metric can be a modulation transfer function, acontrast sensitivity, a derivation thereof, or a combination thereof. Insome embodiments, the first portion can have a shape that comprises aconic, biconic, or biaspheric envelope offset by perturbations of theenvelope comprising an aspheric higher order function of radial distancefrom the optical axis.

Certain embodiments described herein include a lens configured forimplantation into an eye of a human. The lens can include an opticcomprising transparent material. The optic can have an anterior surfaceand a posterior surface. Each of the anterior surface and the posteriorsurface can have a surface vertex. The optic can have an optical axisthrough the surface vertices. At least one of the anterior and posteriorsurfaces can comprise a surface having a first portion and a secondportion. The first portion can have a shape that comprises a conic,biconic, or biaspheric envelope offset by perturbations with respect tothe envelope comprising an aspheric higher order function of radialdistance from the optical axis. The second portion can have a shape thatcomprises a conic, biconic, or biaspheric envelope not offset byperturbations of the envelope comprising an aspheric higher orderfunction of radial distance from the optical axis.

In various embodiments of the lens, the first portion can be disposedcentrally about the optical axis. The second portion can surround saidfirst portion. In some embodiments, the lens can include a third portionsurrounding the second portion. The third portion can have a shape thatcomprises a conic, biconic, or biaspheric envelope offset byperturbations with respect to the envelope comprising an aspheric higherorder function of radial distance from the optical axis. In some suchembodiments, the third portion can have substantially the same conic,biconic, or biaspheric envelope offset by perturbations with respect tothe envelope comprising an aspheric higher order function of radialdistance from the optical axis as the first portion.

Certain embodiments described herein include a lens configured forimplantation into an eye of a human. The lens can include an opticcomprising transparent material. The optic can have an anterior surfaceand a posterior surface. Each of the anterior surface and the posteriorsurface can have a surface vertex. The optic can have an optical axisthrough the surface vertices. At least one of the anterior and posteriorsurfaces can comprise a surface having a first portion and a secondportion. The first portion can be disposed centrally about the opticalaxis. The second portion can surround the first portion. The firstportion can have higher spherical aberration control that providesextended depth of field than the second portion.

In various embodiments, the lens can include a third portion surroundingthe second portion. The third portion can have higher sphericalaberration control that provides extended depth of field than the secondportion. The third portion can have substantially the same sphericalaberration control as the first portion. The first portion can have ashape that comprises a conic, biconic, or biaspheric envelope offset byperturbations from the envelope comprising an aspheric higher orderfunction of radial distance from the optical axis.

In various embodiments of the lens having a third portion, the thirdportion can have a shape that comprises a conic, biconic, or biasphericenvelope offset by perturbations from the envelope comprising anaspheric higher order function of radial distance from the optical axis.

In various embodiments of the lens having a shape that comprises aconic, biconic, or biaspheric envelope offset by perturbations from theenvelope comprising an aspheric higher order function of radial distancefrom the optical axis, the aspheric higher order function can include atleast one even order term, a_(2n)r^(2n), where n is an integer anda_(2n) is a coefficient and r is the radial distance from the opticalaxis. For example, the aspheric higher order function can include asecond order term, a₂r², where a₂ is a coefficient and r is the radialdistance from the optical axis. As another example, the aspheric higherorder function can include a fourth order term, a₄r⁴, where a₄ is acoefficient and r is the radial distance from the optical axis. Theaspheric higher order function can also include a sixth order term, a₆r⁶where a₆ is a coefficient and r is the radial distance from the opticalaxis. Further, the aspheric higher order function can include an eighthorder term, a₈r⁸ where a₈ is a coefficient and r is the radial distancefrom the optical axis.

In various embodiments of the lens having a first and second portion,the lens can further comprise a transition portion providing a smoothtransition without discontinuity between the first and second portions.The transition portion can have a distance between inner and outer radiiin the range of about 0.1-1 mm. The first portion can have a maximumcross-sectional diameter in the range of about 2.5-4.5 mm. For example,the first portion can have a maximum cross-sectional diameter of about3.75 mm. The second portion can have a distance between inner and outerradii in the range of about 1-3.5 mm. In some embodiments, the secondportion can have a distance between inner and outer radii in the rangeof about 0.25-1.5 mm.

In various embodiments of the lens, the optic can have a thickness alongthe optical axis that is in the range of about 100-700 microns (or anyrange formed by any of the values in this range). Alternatively, theoptic can have a thickness along the optical axis that is in the rangeof about 700 microns to 4 millimeters (or any range formed by any of thevalues in this range). In various embodiments, the lens can also includeat least one haptic disposed with respect to the optic to affix theoptic in the eye when implanted therein. In some embodiments, theanterior surface can comprise the surface having the first and secondportions. The posterior surface can comprise a shape having a biconicenvelope.

Certain embodiments described herein include a lens configured forimplantation into an eye of a human. The lens can include an opticcomprising transparent material. The optic can have an anterior surfaceand a posterior surface. Each of the anterior surface and the posteriorsurface can have a surface vertex. The optic can have an optical axisthrough the surface vertices. At least one of the anterior and posteriorsurfaces can comprise a surface having a first portion and a secondportion. The first portion can be disposed centrally about the opticalaxis. The second portion can surround the first portion. The firstportion can be configured to provide an extended depth of field. Thesecond portion can be configured to provide a monofocal distancefocusing.

In some such embodiments, the lens can further comprise a third portionsurrounding the second portion. The third portion can be configured toprovide an extended depth of field. The first portion can have a shapethat comprises a conic, biconic, or biaspheric envelope offset byperturbations with respect to the envelope comprising an aspheric higherorder function of radial distance from the optical axis. In addition,the third portion can have a shape that comprises a conic, biconic, orbiaspheric envelope offset by perturbations with respect to the envelopecomprising an aspheric higher order function of radial distance from theoptical axis.

In various embodiments of the lens having first and second portions,each of the first and second portions can have a caustic. The secondportion can have a conic constant such that the caustic of the secondportion blends smoothly with the caustic of the first portion. In someexamples, the caustic of the second portion blends more smoothly withthe caustic of the first portion than if the second portion comprises aspherical surface. In various embodiments of the lens having a thirdportion, the second and third portions can have a caustic. The secondportion can have a conic constant such that the caustic of the secondportion blends smoothly with the caustic of the third portion. In someexamples, the caustic of the second portion blends more smoothly withthe caustic of the third portion than if the second portion comprises aspherical surface.

In certain embodiments of the lens having first and second portions, theanterior surface can be convex. The posterior surface can be concave.For example, the anterior surface can be convex and the posteriorsurface can be concave such that the optic is meniscus shaped. Invarious other embodiments, the posterior surface can be convex. In someembodiments, the anterior surface can be concave. In addition, invarious embodiments of the lens having first and second portions, thesecond portion can have a shape that comprises a conic, biconic, orbiaspheric envelope not offset by perturbations of the envelopecomprising an aspheric higher order function of radial distance from theoptical axis.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of the human eye.

FIG. 2 is an example lens according to certain embodiments describedherein.

FIG. 3A is an ultrasound of an example lens 200 in accordance withcertain embodiments described herein implanted in the eye. FIG. 3B isthe cross sectional side view of the example lens shown in FIG. 2.

FIG. 4 is a schematic of the cross sectional side view of the optic ofthe lens shown in FIG. 2.

FIG. 5A is a schematic of an example positive meniscus optic.

FIG. 5B is a schematic of an example negative meniscus optic.

FIG. 6A schematically illustrates the depth of field in object space andthe depth of focus in image space.

FIG. 6B schematically illustrates image caustic and circle of confusion.

FIG. 6C schematically illustrates the defocus curves for a standardspherical lens and an idealized hyperfocal eye.

FIG. 6D schematically illustrates an example model to evaluate anddesign a lens in accordance with certain embodiments described herein.

FIGS. 7A-7B are schematics for an example anterior surface and/or aposterior surface of an optic having a first portion configured toprovide extended depth of field, and a second portion configured toprovide enhanced distance visual acuity.

FIGS. 8A-8B are schematics for another example anterior surface and/or aposterior surface of an optic having a first portion configured toprovide extended depth of field, and a second portion configured toprovide enhanced distance visual acuity.

DETAILED DESCRIPTION

Vision problems, such as myopia (nearsightedness), hyperopia(farsightedness), and astigmatism, have been corrected using eyeglassesand contact lenses. Surgical techniques, e.g., laser assisted in-situkeratomileusis (LASIK), have become more common to help address theinconvenience of eyeglasses and contact lenses. In LASIK, a laser isused to cut a flap in the cornea to access the underlying tissue, and toalter the shape of the cornea. In addition, an intraocular lens (IOL)has been used to help treat myopia and cataracts (clouding of thenatural crystalline lens of the eye) by replacing the natural lens ofwith a pseudophakic lens configured to be secured within the capsularbag.

Another solution to treat imperfections in visual acuity is with phakicIOLs. Phakic IOLs are transparent lenses implanted within the eyewithout the removal of the natural crystalline lens. Accordingly, thephakic IOL together with the cornea and the crystalline lens provideoptical power for imaging an object onto the retina. (In contrast,pseudophakic IOLs, which are lenses implanted within the eye to replacethe natural lens, e.g., after removal of the cloudy natural lens totreat cataracts as described above.) Implantation of a phakic IOL can beemployed to correct for myopia, hyperopia, as well as astigmatism,freeing a patient from the inconvenience of eyewear and contacts. PhakicIOL can also be removed, bringing the optics of the eye back toward anatural condition, or replaced to address changing vision correction orenhancement needs of the eye.

With age, people develop presbyopia (inability to focus on nearobjects), which has been addressed with reading glasses in order toprovide the extra refractive power lost when accommodation for nearobjects is no longer attainable. Multifocal contact lenses and IOLs,which provide discrete foci for near and far vision, have also beenused, but the losses in contrast sensitivity and the presence of coaxialghost images in the patient's field of view have made the acceptance ofsuch solutions limited.

Certain embodiments described herein can advantageously provideophthalmic implants for vision correction of, including but not limitedto, myopia, hyperopia, astigmatism, cataracts, and/or presbyopia withextended depth of field and enhanced visual acuity. In variousembodiments, the ophthalmic implants include a lens configured forimplantation into an eye of a patient, for example, a human being. Suchlenses are particularly useful for treating presbyopia and onset ofpresbyopia in middle age populations.

Certain embodiments can include phakic lens implants, where the lens canbe implanted in front of the natural crystalline lens 120, such asbetween the cornea 110 and the iris 115. Other embodiments areconfigured to be placed between the iris 115 and natural crystallinelens 120. Some example embodiments include lenses for treating myopia,hyperopia, astigmatism, and/or presbyopia.

Some other embodiments can include a pseudophakic lens implanted withinthe eye, for example, in the capsular bag, after removal of thecrystalline lens 120. As discussed above, a pseudophakic lens can beused for treating cataracts as well as for providing refractivecorrection.

FIG. 2 is an example lens 200 according to various embodiments describedherein. The lens 200 can include an optical zone or optic 201. The optic201 transmits and focuses, e.g., refracts, light received by the lens200. As will be described in more detail herein, the optic 201 cancomprise a surface shape of one or more surfaces of the optic 201designed to refract and focus light and increase the depth of field andvisual acuity. For example, in some embodiments, the surface shapes ofthe surfaces of the optic 201 can be designed such that the optic 201can continuously focus light for high visual acuity, e.g., 20/20 vision,for a wide range of object vergences (e.g., vergences within the rangeof at least about 0 to about 2.5 Diopter, in some implementations fromat least about 0 diopter to at least about 1.8, 1.9, 2.0, 2.1, 2.2, 2.3,2.4, 2.5, 2.6, 2.7, 2.8, 2.9, or 3.0 diopters or possibly from at leastabout 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, or 0.7 diopter to at least about 2.52.6, 2.7, 2.8, 2.9, or 3.0 diopters) onto the retina to increase thedepth of field. Furthermore, in some embodiments, the surface shapes ofthe surfaces of the optic 201 can be designed such that the images aresubstantially coaxial and of substantially similar magnitude to reducethe presence of ghost images.

As shown in FIG. 2, the example lens 200 can also include a haptic 205.In some embodiments, the haptic 205 can include one or more haptics orhaptic portions 205 a, 205 b, 205 c, and 205 d to stabilize the lens inand attach the lens 200 to the eye. For example, in FIG. 2, the hapticportions 205 a, 205 b, 205 c, and 205 d are disposed about the optic 201to affix the optic 201 in the eye when implanted therein. In variousembodiments, the lens and in particular the haptics are configured to beimplanted outside the capsulary bag, for example, forward the naturallens as for a phakic IOL design. As discussed above, the phakic IOLimplant may be configured for implantation between the iris and thenatural lens. Accordingly, in certain embodiments, the haptic 205 isvaulted such that the optic 201 is disposed along a central optical axisof the eye at a location anterior of the location of contact pointsbetween the haptic portions 205 a-205 d. The configuration enhancesclearance between the optic 201 and the natural lens in a phakic eye,which natural lens flexes when the eye accommodates. In some cases, thehaptic 205 is configured to provide minimum clearance to the naturallens when implanted that reduce, minimize or prevents contact between ananterior surface of the natural lens and a posterior surface of theoptic 201. With some materials, contact between the optic 201 and theanterior surface of the natural lens is permitted. In some embodiments,the lens 200 can be implanted across the pupil or the opening of theiris 115, and when in place, the haptic portions 205 a, 205 b, 205 c,and 205 d can be placed under the iris 115. Although the haptic 205shown in FIG. 2 includes four haptic portions 205 a, 205 b, 205 c, and205 d in the shape of extended corner portions, the shape, size, andnumber of haptics or haptic portions are not particularly limited.

In various implementations, for example, the lens is configured forimplantation within the capsular bag after removal of the natural lens.Such pseudophakic lens may have haptics having a shape, size and/ornumber suitable for providing secure placement and orientation withinthe capsular bag after implantation. FIG. 3A is an ultrasound of anexample lens 200 in accordance with certain embodiments described hereinimplanted in the eye.

The optic 201 can include a transparent material. For example, thetransparent material can include a collagen copolymer material, ahydrogel, a silicone, and/or an acrylic. In some embodiments, thetransparent material can include a hydrophobic material. In otherembodiments, the transparent material can include a hydrophilicmaterial. Other materials known or yet to be developed can be used forthe optic 201.

Certain embodiments of the optic 201 can advantageously include acollagen copolymer material, e.g., similar to material used in Collamer®IOLs by STAAR® Surgical Company in Monrovia, Calif. An example collagencopolymer material is hydroxyethyl methacrylate (HEMA)/porcine-collagenbased biocompatible polymer material. Since collagen copolymer materialscan have characteristics similar to that of the human crystalline lens,certain embodiments of the lens described herein can perform opticallysimilar to the natural lens. For example, in some embodiments, due tothe anti-reflective properties and water content of about 40%, a lens200 made with a collagen copolymer material can transmit light similarto the natural human crystalline lens. Less light can be reflectedwithin the eye, leading to sharper, clearer vision, and feweroccurrences of glare, halos, or poor night vision compared with lensesmade with other lens materials.

In some embodiments of the lens 200 made with a collagen copolymermaterial, the lens 200 can be flexible, allowing easy implantationwithin the eye. In addition, because collagen copolymer materials aremade with collagen, various embodiments of the lens 200 arebiocompatible with the eye. In some embodiments, the lens 200 canattract fibronectin, a substance found naturally in the eye. A layer offibronectin can form around the lens 200, inhibiting white cell adhesionto the lens 200. The coating of fibronectin can help prevent the lens200 from being identified as a foreign object. In addition, like thecollagen it contains, various embodiments of the lens 200 can carry aslight negative charge. Since proteins in the eye also carry a negativecharge, as these two negative forces meet along the border of the lens200, the charge repulsion can help push away the proteins from the lens200. As such, the lens 200 can naturally keep itself clean and clear.

Furthermore, in some embodiments, the lens 200 can include anultraviolet (UV) blocker. Such a blocker can help prevent harmful UVAand UVB rays from entering the eye. Accordingly, certain embodiments canhelp prevent the development of UV related eye disorders.

In some embodiments, the haptic 205 (or one or more of the hapticportions 205 a, 205 b, 205 c, and 205 d) can also be made of the samematerial as the optic 201. For example, the haptic 205 can be made of acollagen copolymer, a hydrogel, a silicone, and/or an acrylic. In someembodiments, the haptic 205 can include a hydrophobic material. In otherembodiments, the haptic 205 can include a hydrophilic material. Othermaterials known or yet to be developed can also be used for the haptic205.

The lens 200 can be manufactured by diamond turning, molding, or othertechniques known in the art or yet to be developed. In some embodimentsof the lens 200 manufactured with a collagen copolymer material, thelens 200 can be machined in a dry state, followed by hydration tostabilize the lens 200. A similar approach can be employed for othermaterial as well.

FIG. 3B is the cross sectional side view of the example lens 200 shownin FIG. 2; and FIG. 4 is a schematic of the cross sectional side view ofthe optic 201 of the lens 200. The optic 201 has an anterior surface 201a and a posterior surface 201 b. The optic 201 also has a center throughwhich the optical axis of the lens passes and a thickness T_(c) at thecenter along the optical axis. The optical axis passes through thesurface vertices of the anterior and posterior surfaces 201 a, 201 b.The exact size of the optic 201 can depend on the patient's pupil size,the material of the lens 200, and the patient's prescription. In someembodiments, for example, for phakic lenses, the thickness at the centerT_(c) of the optic 201 can be made relatively thin. For example, thethickness at the center T_(c) of the optic 201 can be about 100 to about700 micrometers, about 100 to about 600 micrometers, about 100 to about500 micrometers, about 100 to about 400 micrometers, about 100 to about300 micrometers, or about 100 to about 200 micrometers, such that thelens 200 can be relatively unnoticeable to the patient and to others.Thinner lenses also simplify the process of insertion of the lensthrough the eye tissue, e.g., cornea. For example, the optic could havea thickness along the optical axis of about 110, 115, 120, 130, 140, or150 to about 200, 300, or 400 micrometers, any values between any ofthese thicknesses, or any ranges formed by any of these thicknesses. Thethickness at the center T_(c) of the optic 201 can thus be any thicknessin between the above mentioned values, e.g., thickness in ranges betweenany of the following: 100 micrometers, 110 micrometers, 115 micrometers,120 micrometers, 130 micrometers, 140 micrometers, 150 micrometers, 200micrometers, 250 micrometers, 300 micrometers, 350 micrometers, 400micrometers, 450 micrometers, 500 micrometers, 550 micrometers, 600micrometers, 650 micrometers, or 700 micrometers.

In some other embodiments for example, for pseudophakic lenses where thelens 201 replaces the natural crystalline lens, the thickness at thecenter T_(c) of the optic 201 can be thicker than those for phakiclenses, e.g., about 700 micrometers to about 4 mm, about 700 micrometersto about 3 mm, about 700 micrometers to about 2 mm, about 700micrometers to about 1 mm, any value in between such ranges, or anyranges formed by any of the values in these ranges. For example, thethickness at the center T_(c) of the optic 201 can be about 700micrometers, about 800 micrometers, about 900 micrometers, about 1millimeter, about 1.5 millimeters, about 2 millimeters, about 2.5millimeters, about 3 millimeters, about 3.5 millimeters, or about 4millimeters or ranges therebetween. However, even for pseudophakiclenses the lens may employ smaller thicknesses, T_(c), for example,thicknesses between about 300 micrometers to 700 micrometers, forexample, 300 micrometers, 400 micrometers, 500 micrometers, 600micrometers or 700 micrometers or any ranges therebetween such as 300 to400 micrometer, 400 to 500 micrometers, 500 to 600 micrometers.

In accordance with certain embodiments described herein, the anteriorsurface 201 a is convex and the posterior surface 201 b is concave suchthat the optic 201 is meniscus shaped. FIGS. 5A and 5B are example crosssectional side views of the optic 201 being meniscus shaped. A meniscusshaped optic 201 can be quite advantageous when used for example, in aphakic lens. For example, when implanted behind (or posterior of) theiris and in front of (or anterior of) the natural lens, an anteriorsurface 201 a of the optic 201 that is convex can help prevent chaffingof the iris adjacent to that surface 201 a, and a posterior surface 201b of the optic 201 a that is concave can help prevent damage to thenatural lens adjacent to that surface 201 b, which may result in, forexample, cataracts.

The meniscus shaped optic can be described as either positive ornegative. As shown in FIG. 5A, a positive meniscus optic 301 has asteeper curving convex surface 301 a than the concave surface 301 b, andhas a greater thickness at the center T_(c) (through which the opticalaxis passes) than at the edge T_(c). In contrast, as shown in FIG. 5B, anegative meniscus optic 401 has a steeper curving concave surface 401 bthan the convex surface 401 a, and has a greater thickness at the edgeT_(c) than at the center T_(c). In certain embodiments, a positivemeniscus optic can be used to treat hyperopia, while in otherembodiments, a negative meniscus optic can be used to treat myopia.

In various embodiments, the optic 201 is not meniscus shaped. Forexample, in some embodiments, the anterior surface 201 a issubstantially flat and the posterior surface 201 b is concave such thatthe optic 201 is plano-concave. In other embodiments, both the anteriorsurface 201 a and the posterior surface 201 b are concave such that theoptic 201 is biconcave. In further embodiments, the anterior surface 201a is convex and the posterior surface 201 b is substantially flat suchthat the optic 201 is plano-convex. In yet further embodiments, both theanterior surface 201 a and the posterior surface 201 b are convex suchthat the optic 201 is biconvex.

In certain embodiments, the anterior surface 201 a and/or the posteriorsurface 201 b of the optic 201 can include aspheric surfaces. Forexample, the anterior surface 201 a and/or the posterior surface 201 bof the optic 201 can include a surface shape that is not a portion of asphere. In various embodiments, the anterior surface 201 a and/or theposterior surface 201 b can be rotationally symmetric. For example, thesurface profile or sag of the aspheric shape can include at least aconic term. The conic term can be described as:

$\begin{matrix}{{z = \frac{{cr}^{2}}{1 + \sqrt{1 - {\left( {1 + k} \right)c^{2}r^{2}}}}},} & (1)\end{matrix}$

where c is the curvature of the surface (or the inverse of the radius),k is the conic constant, and r is the radial distance from the surfacevertex.

In some embodiments, the aspheric shape can include a conic offset byperturbations comprising, for example, a higher order function of radialdistance from the surface vertex. Thus, the sag of the aspheric shapecan include the conic term and a higher order function of radialdistance from the surface vertex. The higher order function can describethe aspheric perturbations from the conic term. In some embodiments, thehigher order function can include at least one even order terma_(2n)r^(2n), where n is an integer, a_(2n) is a coefficient, and r isthe radial distance from the surface vertex. For example, the asphericshape can be described using the conic term and the even-poweredpolynomial terms (e.g., describing an even asphere):

$\begin{matrix}{{z(r)} = {\frac{{cr}^{2}}{1 + \sqrt{1 - {\left( {1 + k} \right)c^{2}r^{2}}}} + {a_{2}r^{2}} + {a_{4}r^{4}} + {a_{6}r^{6}} + {a_{8}r^{8}} + {\ldots \mspace{14mu}.}}} & (2)\end{matrix}$

As can be seen in the example equation (2), the higher order functioncan include at least a second order term (a₂r²), a fourth order term(a₄r⁴), a sixth order term, (a₆r⁶), and/or an eighth order term (a₈r⁸).In some embodiments, the higher order function can include one or moreodd order terms. For example, the higher order function can include onlyodd order terms or a combination of even and odd order terms.

As also shown in equation (2), the surface shape can depend on the conicconstant k. If the conic constant k=0, then the surface is spherical.Thus, in some embodiments, k has a magnitude of at least zero, such that|k|≥0. In some embodiments, k has a magnitude greater than zero, suchthat |k|>0. In various embodiments, k has a magnitude of at least one,such that |k|≥1. In some embodiments, |k|≥2, |k≥3, |k|≥5, |k|≥7, or|k|≥10. For example, k≤−1, k≤−2, k≤−3, k≤−5, k≤−7, k≤−10. In variousembodiments, therefore, the surface has a shape of a hyperbola. However,in certain embodiment, the magnitude of the conic constant may be lessthan one, e.g., 0≤|k|≤1.

In various embodiments, the anterior surface 201 a and/or the posteriorsurface 201 b can be rotationally non-symmetric and have differentcurvature along different directions through the center and/or opticalaxis of the optic 201. For example, the anterior surface 201 a and/orthe posterior surface 201 b can have different curvature alongorthogonal directions through the center of the optic 201. Certain suchembodiments can be advantageous for treating astigmatism, wherecorrection along different directions (meridians) can be desired.

In some embodiments, the sag of the rotationally non-symmetric surfacecan include at least a biconic term. A biconic surface can be similar toa toroidal surface with the conic constant k and radius different in thex and y directions. The biconic term can be described as:

$\begin{matrix}{{z = \frac{{c_{x}x^{2}} + {c_{y}y^{2}}}{1 + \sqrt{1 - {\left( {1 + k_{x}} \right)c_{x}^{2}x^{2}} - {\left( {1 + k_{y}} \right)c_{y}^{2}y^{2}}}}},} & (3)\end{matrix}$

where c_(x) is the curvature of the surface in the x direction (or theinverse of the radius in the x direction), and c_(y) is the curvature ofthe surface in they direction (or the inverse of the radius in the ydirection) while k_(x) is the conic constant for the x direction, andk_(y) is the conic constant for they direction.

In some embodiments, the aspheric shape can include the biconic offsetby perturbations comprising a higher order function of radial distancefrom the surface vertex. Thus, similar to equation (2), the sag of theaspheric shape can include the biconic term and a higher order function.The higher order function can include at least one even order term,e.g., at least a second order term (a₂r²), a fourth order term (a₄r⁴), asixth order term, (a₆r⁶), and/or an eighth order term (a₈r⁸). Forexample, similar to equation (2), the higher order function can bea₂r²+a₄r⁴+a₆r⁶+a₈r⁸+ . . . .

In some embodiments, the higher order function can include one or moreodd order terms. For example, the higher order function can include onlyodd order terms or a combination of even and odd order terms.

Accordingly, as described herein, the anterior surface 201 a and/or theposterior surface 201 b of the optic 201 can have a shape that includesa conic term (with or without a higher order function) or a biconic term(with or without a higher order function).

One example for vision correction for presbyopia and/or astigmatismincludes an anterior surface 201 a and a posterior surface 201 b bothhaving an aspheric surface. The aspheric surface of the anterior surface201 a has a shape that includes a conic term offset by perturbationscomprising second, fourth, sixth, and eighth order terms; and theaspheric surface of the posterior surface 201 b has a shape thatincludes a biconic term. The sag of the example aspheric anteriorsurface 201 a can be given as:

$\begin{matrix}{{z(r)} = {\frac{{cr}^{2}}{1 + \sqrt{1 - {\left( {1 + k} \right)c^{2}r^{2}}}} + {a_{2}r^{2}} + {a_{4}r^{4}} + {a_{6}r^{6}} + {a_{8}{r^{8}.}}}} & (4)\end{matrix}$

Furthermore, the sag of the example posterior surface 201 b, which canbe biconic, can be given as:

$\begin{matrix}{{z = \frac{{c_{x}x^{2}} + {c_{y}y^{2}}}{1 + \sqrt{1 - {\left( {1 + k_{x}} \right)c_{x}^{2}x^{2}} - {\left( {1 + k_{y}} \right)c_{y}^{2}y^{2}}}}},} & (5)\end{matrix}$

which is similar to equation (3). Certain embodiments of such a lens maybe, although is not limited to, a meniscus lens.

Other examples are possible. In certain embodiments, the particularshape (e.g., curvature of anterior surface, curvature of posteriorsurface, conic constants, coefficients of the higher order function,etc.) of the optic 201 can depend on the patient's prescription.

As some examples, for lenses having a nominal dioptric power betweenabout −18 D to about 6 D sphere with 0 to about 2 D cylinder, with 0 toabout 3 D cylinder, or with 0 to about 4 D cylinder, the followingnon-limiting example design parameters can be used in certainembodiments. The radius R of the anterior surface (e.g., the inverse ofthe curvature) can be between about −100 mm to about 100 mm, about −50mm to about 50 mm, about −10 mm to about 10 mm, or about −5 mm to about5 mm. In some examples, R of the anterior surface can be between about−1 mm to about 1 mm or 0 to about 1 mm. For example, the radius of theanterior surface can be between 0 to about 1×10⁻² mm, between about1×10⁻⁷ mm to about 5×10⁻³ mm, between about 1×10⁻⁶ mm to about 1×10⁻³mm, or between about 5×10⁻⁶ mm to about 5×10⁻⁴ mm.

As described herein, in various embodiments, k of the anterior surfacecan have a magnitude greater than zero such that |k|>0. In someembodiments, k has a magnitude of at least one, such that |k|≥1. In someembodiments, |k|≥2, |k|≥3, |k|≥5, |k|≥7, or k|≥10. For example, k≤−1,k≤−2, k≤−3, k≤−5, k≤−7, k≤−10. In some embodiments, k<<−10. For example,in some embodiments, k can be between about −1×10⁶ to −100, betweenabout −5×10⁵ to about −5×10⁴, or between about −3×10⁵ to about −2×10⁵.

Accordingly, in various embodiments the magnitude of the ratio of theconic constant of the anterior surface and the radius of curvature ofthe anterior surface may be between 10⁴ and 10¹⁴, between 10⁶ and 10¹²,between 10⁸ and 10¹¹, between 10⁹ and 10¹¹, between 10⁸ and 10¹⁰,between 10⁹ and 10¹⁰, in various embodiments.

The coefficient a₂ for the second order term of the anterior surface invarious embodiments can be between 0 to about 1. For example, a₂ can bebetween 0 to about 0.5, between about 0.001 to about 0.3, or betweenabout 0.005 to about 0.2.

The coefficient a₄ for the fourth order term of the anterior surface invarious embodiments can be between about −1 to 0. For example, a₄ can bebetween about −0.1 to 0, between about −0.05 to about −1×10⁻⁴, orbetween about −0.01 to about −1×10⁻³.

The coefficient a₆ for the sixth order term of the anterior surface invarious embodiments can be between 0 to about 1. For example, a₆ can bebetween 0 to about 0.1, between 0 to about 0.01, or between about 0.0001to about 0.001.

In addition, the coefficient a₈ for the eighth order term of theanterior surface in various embodiments can be between about −1 to 0.For example, a₈ can be between about −0.001 to 0, between about −0.0005to 0, or between about −0.0001 to 0.

Furthermore, for lenses having a nominal dioptric power between about−18 D to about 6 D sphere with 0 to about 2 D cylinder, with 0 to about3 D cylinder, or with 0 to about 4 D cylinder, the followingnon-limiting example design parameters can be used in certainembodiments for the posterior surface. The radius R_(y) of the posteriorsurface in the y direction (e.g., the inverse of the curvature in the ydirection) can be between 0 to about 20 mm. For example, the radiusR_(y) of the posterior surface can be between 0 to about 15 mm, betweenabout 2 mm to about 13 mm, or between about 3 mm to about 14 mm, orbetween about 4 mm to about 10 mm.

In various embodiments, k_(y) of the posterior surface can be betweenabout −20 to about 20, between about −18 to about 15, or between about−15 to about 5. In some such embodiments, k_(y) of the posterior surfacedoes not necessarily have a magnitude of at least one. For example,k_(y) can be between about −1 to about 1. In various embodiments,|k_(y)| is greater than zero.

The radius R_(x) of the posterior surface in the x direction (e.g., theinverse of the curvature in the x direction) can be between 0 to about20 mm. For example, the radius of the posterior surface can be between 0to about 15 mm, between 0 to about 12 mm, or between 0 to about 10 mm.

In various embodiments, k_(x) of the posterior surface can be betweenabout −25 to 0, between about −20 to 0, between about −18 to 0, betweenabout −17.5 to 0, or between about −15.5 to 0. In various embodiments,|k_(x)| is greater than zero.

Although the example design parameters of R, k, a₂, a₄, a₆, and a₈ forlenses having the above given nominal dioptric power were given for theanterior surface, and the example design parameters of R_(y), k_(y),R_(x), and k_(x) were given for the posterior surface, the ranges ofvalues for R, k, a₂, a₄, a₆, and a₈ can be used for the posteriorsurface, and the ranges of values for R_(y), k_(y), R_(x), and k_(x) canbe used for the anterior surface. Additionally, although the anteriorsurface included the higher order aspheric perturbation terms (e.g., a₂,a₄, a₆, and a₈), the higher order aspheric perturbation terms (e.g., a₂,a₄, a₆, and a₈) can be used for the posterior surface instead of theanterior surface or for both the anterior and posterior surfaces. Anyone or more of the values in these ranges can be used in any of thesedesigns.

Furthermore, as described herein, the particular shape of variousembodiments can be designed to increase the depth of field and toincrease visual acuity. As shown in FIG. 6A, the depth of field can bedescribed as the distance in front of and beyond the subject in objectspace that appears to be in focus. The depth of focus can be describedas a measurement of how much distance exists behind the lens in imagespace wherein the image will remain in focus. To increase the depth offield, the surface shape of the anterior surface 201 a and/or thesurface shape of the posterior surface 201 b of the optic 201 can besuch that for a wide range of object vergences, the light rays arefocused onto the retina or sufficiently close thereto. To increasevisual acuity and reduce ghosting, the surface shape of the anterior 201a and/or the surface shape of the posterior surface 201 b of the optic201 also can be such that the images for an on-axis object aresubstantially on-axis and of similar magnitude with each other.

In certain such embodiments, the image caustic can be sculpted for thevergence range of about 0 to about 2.5 Diopters or more although thisrange may be larger or smaller. As shown in FIG. 6B, in someembodiments, the image caustic can be described as the envelop producedby a grid of light rays, and the circle of confusion can be described asan optical spot caused by a cone of light rays from a lens not coming toa perfect focus when imaging a point source. Thus, the image caustic canbe sculpted such that the circle of confusion is substantially stablehaving a similar sizes for a range of longitudinal positions along theoptical axis and relatively small. The design may sacrifice the size ofthe circle of confusion at some longitudinal positions along the opticalaxis to permit the circle of confusion to be larger for otherslongitudinal positions with the net result of providing circles ofconfusion having similar size over a range of longitudinal positionsalong the optical axis.

In certain embodiments, the surface shape of the anterior surface 201 aand/or the surface shape of the posterior surface 201 b can bedetermined such that the image caustic is sculpted around the hyperfocalplane of the eye. In some embodiments, the hyperfocal distance can bedescribed as the focus distance which places the maximum allowablecircle of confusion at infinity, or the focusing distance that producesthe greatest depth of field. Accordingly, in certain embodiments, toincrease the depth of field, the surface shape of the anterior surface201 a and/or the surface shape of the posterior surface 201 b of theoptic 200 can be such that the light rays are refocused to thehyperfocal distance.

In various embodiments, the surface shape of the anterior surface 201 aand/or the surface shape of the posterior surface 201 b of the optic 201can be evaluated and designed using the defocus curves of the lens. Adefocus curve can portray the response of a retinal image qualityparameter, such as contrast, as a function of different vergences. Anobject at infinity has a vergence of 0 Diopter. FIG. 6C illustrates thedefocus curves for a standard spherical lens and an idealized hyperfocaleye. As shown in the figure, although the contrast can decrease (due topreservation of the areas under the curves), the idealized hyperfocaleye has a stable or substantially stable (e.g., similar or substantiallyconstant) contrast for a range of vergences.

In certain embodiments, the surface shape of the anterior surface 201 aand/or the surface shape of the posterior surface 201 b of the optic 201can be evaluated and/or designed using the Liou-Brennan model eye suchas under Best Corrected Distance Visual Acuity (BCDVA) conditions. FIG.6D illustrates a schematic of an example phakic lens according tocertain embodiments described herein modeled with the Liou-Brennan modeleye. As shown in FIG. 6D, the lens 200 can be positioned between theiris 515 and in front of the “natural” crystalline lens 520 in themodel. As also shown in FIG. 6D, the model can simulate light raysentering the eye 500 through the cornea 510, the lens 200, and the“natural” crystalline lens 520 and towards the retina 530. The model canbe used for the polychromatic wavelengths between the range of about 400nanometers to about 700 nanometers. The model can also be used with adual-gradient index lens profile (e.g., to model astigmatism).Pseudophakic lenses according to certain embodiments described hereincan also be modeled with the Liou-Brennan model eye with the lenspositioned in place of the “natural” crystalline lens 520.

Other models known in the art or yet to be developed can also be used.For example, the surface shape of the anterior surface 201 a and/or thesurface shape of the posterior surface 201 b of the optic 201 can alsobe evaluated and/or designed using a Badal model eye, an Arizona modeleye (University of Arizona model), an Indiana model eye (IndianaUniversity model), an ISO model eye, or any standardized or equivalentmodel eye. In addition, the simulations can be performed using raytracing and/or design software known in the art or yet to be developed.As one example software, Zemax design software by Zemax, LLC in Redmond,Wash. can be used for some embodiments. The physical limitations of theenvironment, for example, the placement of the IOL anterior to thenatural lens are useful for performing simulations for a phakic lensdesign. Such simulations can simultaneously evaluate performance (e.g.,RMS wavefront error across the complete pupil) for multiple vergences aninclude contributions from the different vergences in a merit functionthat is optimized. Multiple wavefronts are thus evaluated in unison toarrive at a balanced design that provides substantially similar sizedcircles of confusion through a range of locations along the opticalaxis. Varying pupil size for different vergences can also be employed.

In certain embodiments, the surface shape of the anterior surface 201 aand/or the surface shape of the posterior surface 201 b of the optic 201can be advantageously evaluated and designed such that for the visiblewavelengths, light from an on-axis object is focused substantiallyon-axis, with substantially similar magnitude, and substantially on theretina within the range of at least about 0 Diopter to about 2.5Diopter. By controlling the different orders of spherical aberrations(e.g., which can be correlated with the higher order aspheric terms inequation (2)) to achieve a substantially similar size cross-sections ofthe caustic for different longitudinal positions along the optical axisnear the retina, and including the toric balancing and correction (e.g.,the biconic term in equation (3)) when necessary to treat patients withastigmatism, the radial power profile of the lens 200 can be describedas:

Φ(r)=a+br ² +cr ⁴ +dr ⁶ +er ⁸,  (6)

where a, b, c, d, and e are real numbers. Additionally, in variousembodiments, the surface shape of the anterior surface 201 a and/or thesurface shape of the posterior surface 201 b of the optic 201 can beevaluated and designed to account for the Stiles-Crawford effect.Furthermore, the surface shapes can also be designed to consider thepupil sizes varying with illumination and/or object vergence.

To describe the performance of the lens 200, the modulation transferfunction (MTF) can be used in some embodiments. For example, the MTF candescribe the ability of the lens 200 to transfer contrast at aparticular resolution from the object to the image. In variousembodiments of the lens 200, the anterior surface 201 a and theposterior surface 201 b can be shaped to provide MTF values forwavelengths between the range of about 400 nanometers to about 700nanometers (weighted by photopic, scotopic and/or mesopic distributions)that are between about 0.1 and about 0.4 at spatial frequencies of about100 line pairs per millimeter (e.g., 20/20 vision) for at least about90%, at least about 95%, at least about 97%, at least about 98%, or atleast about 99% of the object vergences within the range of at leastabout 0 Diopter to about 2.0, 2.1, 2.2, 2.3, 2.4 or 2.5 Diopter (or toabout 2.6, 2.7, 2.8, 2.9, 3.0) when the optic 201 is inserted into aneye. For example, the eye could be a human eye having an aperturediameter of at least about 2 millimeters, at least about 3 millimeters,at least about 4 millimeters, for example, 2 to 6 millimeters, 3 to 6millimeters, or 4 to 6 millimeters. The MTF values may thus be 0.1, 0.2,0.3, or 0.4 or any range therebetween. Additionally, in variousimplementations, the anterior and posterior surfaces are shaped toprovide modulation transfer functions without phase reversal for atleast 90%, 95%, or 97%, up to 98%, 99%, or 100% of the object vergenceswithin the range of 0 D to 2.5 D (or alternatively to 2.0, 2.1, 2.2,2.3, 2.4, 2.6, 2.7, 2.8, 2.9, or 3.0 Diopter) when said optic isinserted into a model eye having an aperture size of 2 to 6 millimeters,3 to 6 millimeters, or 4 to 6 millimeters. In some embodiments, when thehuman eye includes a crystalline lens, such MTF values can be providedwhen the optic 201 is inserted anterior of the crystalline lens. Inother embodiments, when the human eye excludes a crystalline lens, suchMTF values can be provided when the optic 201 is inserted in place ofthe crystalline lens. The MTF values may comprise average MTF values andmay be calculated by integrating over the wavelength range which isweighted by any of the photopic, scotopic, mesopic distributions orcombinations thereof.

As other examples, the eye could be a model eye (e.g., Liou-Brennan,Badal, Arizona, Indiana, ISO model eye, or any standardized orequivalent model eye) that models the human eye as opposed to a humaneye itself. For example, the model eye in some embodiments can alsoinclude a Liou-Brennan model eye. In some embodiments, such MTF valuescan be provided when the optic 201 is inserted in the model eye in aphakic configuration. In other embodiments, such MTF values can beprovided when the optic 201 is inserted in a pseudophakic configuration.

Various implementations described herein comprise a single refractivelens that can be implanted in the eye, for example, posterior of thecornea. In certain implementations the refractive lens is configured tobe implanted between the iris and the natural lens. In otherimplementations, the refractive lens is configured to be implanted inthe capsular bag after removal of the natural lens. In variousimplementations, the refractive lens is not a diffractive lens and isdevoid of a diffraction grating on the surfaces thereof. In variousimplementations, the refractive lens does not have discrete spaced apartfoci. The anterior and posterior surfaces, for example, are shaped so asnot to produce discrete foci where light is focused along the opticalaxis of the lens that are spaced apart from each other by regions wherelight is substantially less focused as provided in conventionalmultifocal lenses. Such multifocal design with discrete foci havemultiple peaks of focused energy or of energy density at differentlocations on the optical axis.

Various implementations described herein can provide treatment for earlyonset and progression of presbyopia without need for laser surgery orreading glasses. Implementations may provide about 2.0 D of near as wellas intermediate viewing. Depth of field for range over 2 D for anaperture of 5.0 mm can be provided.

Various embodiments may be employed to provide modified monovisionsolutions. For example, a first lens may be provided that has anextended depth of focus for object vergences over 0 to 2.0 D or over 0to 2.5 D and second lens may be provided that has an extended depth offocus for object vergences over −2.0 to 0 D or over −2.5 to 0 D. Theserespective lenses may be implanted in the patient's dominant andnon-dominant respectively. A patient may then be provided with extendeddepth's of field that are different for each of the left and right eye.However the aggregate depth of field is larger than provided by one ofthe first or second lenses along. The design details of such lenses mayotherwise be similar to those discussed above.

As described herein, various embodiments include a lens with extendeddepth of field. For example, with reference to lens 200 described herein(e.g., as shown in FIGS. 2-4), the lens 200 can include an optic 201having an anterior surface 201 a and/or a posterior surface 201 b havinga shape designed to increase the depth of field. In certain embodiments,the anterior surface and/or the posterior surface of the optic can alsoinclude a portion designed to improve distance vision (e.g. enhancedistance visual acuity) yet still provide extended depth of field.

FIGS. 7A-7B are schematics for an example anterior surface and/or aposterior surface of such an optic. The anterior surface and theposterior surface can have a surface vertex. The optic can have anoptical axis through the surface vertices. The anterior surface and/or aposterior surface of the example optic 700 can include a surface havinga first portion 701 and a second portion 702. The first portion 701 canbe configured to provide extended depth of field and the second portion702 can be configured to provide monofocal distance correction andfocusing. Referring to the defocus curves shown in FIG. 6C, the firstportion 701 can have a defocus curve similar in shape to that of the“ideal” hyperfocal defocus curve, and the second portion 702 can have adefocus curve similar in shape to that of the standard spherical(monofocal) lens. Accordingly, the first portion 701 can be configuredto provide extended depth of field, and the second portion 702 can beconfigured to provide enhanced distance vision or distance visualacuity. For example, the first portion 701 configured to provide anextended depth of field can supply near-equal visual acuity, or at leastmore than for the second portion 702, throughout a range of focus (e.g.,far or distance, intermediate, near), while the second portion 702 canprovide an enhanced vision quality metric for distance in comparison tothe first portion 701. The enhanced vision quality metric can be afigure of merit for objects at distance (e.g., at or near 0.0 D).Objects between infinity and 2 meters (e.g., infinity to 2 meters,infinity to 3 meters, infinity to 4 meters, infinity to 5 meters,infinity to 6 meters, infinity to 7 meters, infinity to 8 meters,infinity to 9 meters, infinity to 10 meters, or any ranges in betweenany of these ranges) are considered distance. The figure of merit can bea modulation transfer function (MTF), a contrast sensitivity (CS),contrast, a derivation thereof, or a combination thereof. Other metricscan also be used to characterize image quality at the distance focus(which corresponds to the base power or labeled power of the lens) orfor far objects. In some instances, the enhanced vision quality metriccan be a higher value for the second portion 702 than for the firstportion 701.

FIG. 7B illustrates how rays passing through the second portion 702 arefocused on the distance vision focus (labeled as 0). (As referencedabove, this distance vision focus corresponds to the base power, labeledpower, or distance power of the lens.) In contrast, rays passing throughthe first portion 701 form a caustic of near constant diameter throughthe far (0), intermediate (1), and near (2) foci as opposed to a singlesharp focus at the distance (0), intermediate (1) or near (2) planesthereby providing an extended depth of field.

As shown in FIGS. 7A-7B, the first portion 701 can be disposed centrallywithin the optic 700. In some cases, the first portion is disposedcentrally about the optical axis. The first portion 701 can have amaximum cross-sectional diameter in the range of about 2.5-4.5 mm (e.g.,2.5 mm, 2.75 mm, 3.0 mm, 3.25 mm, 3.5 mm, 3.75 mm, 4.0 mm, 4.25 mm, 4.5mm, or any ranges between any of these sizes). Larger or smaller sizesmay also be possible. The first portion 701 can have a surface profileas described herein with respect to optic 201 to provide extended depthof field. For example, the first portion 701 may introduce sphericalaberration to provide extended depth of field. In some such examples, asdescribed herein, the first portion 701 can have a shape comprising aconic or a biconic envelope offset by perturbations from the envelopecomprising an aspheric higher order function of radial distance from theoptical axis. Equation (2) describes an example shape using a conic termand even-powered polynomial terms. Other examples and combinations arepossible. For example, the first portion 701 can have a shape comprisinga biaspheric envelope. The biaspheric envelope can include two asphericcross-sections in two orthogonal directions. In some instances, thebiaspheric envelope can be offset by perturbations comprising anaspheric higher order function of radial distance from the optical axis.

The second portion 702 can surround the first portion 701. The secondportion 702 can extend from the first portion 701 to the end of theoptic 700. Accordingly, in some examples, the width of the secondportion 702 can be the distance between the outer periphery of the firstportion 701 to the edge of the optic 700. For example, the secondportion 702 can have a width (e.g., a distance between inner and outerradii) in the range of about 1.0-3.5 mm (e.g., 1.0 mm, 1.25 mm, 1.5 mm,1.75 mm, 2.0 mm, 2.25 mm, 2.5 mm, 2.75 mm, 3.0 mm, 3.25 mm, 3.5 mm, orany ranges between any of these sizes). Sizes outside these ranges arealso possible.

The second portion 702 can have a different surface profile than thefirst portion 701. The first portion 701 can have higher sphericalaberration control that provides extended depth of field than the secondportion 702. In some cases, the second portion 702 may havesubstantially no spherical aberration control or at least no aberrationcontrol that provides extended depth of focus. For example, the secondportion 702 can have a shape that comprises a conic, biconic, orbiaspheric envelope not offset by perturbations comprising an aspherichigher order function of radial distance from the optical axis. In somecases, the second portion can have a shape that is spherical.

The second portion 702 can allow greater control of the marginal rays ofthe system such that a higher percentage of the rays that propagatethrough this portion are focused on the retina potentially providingincreased contrast or improved vision quality as measure by othermetrics for objects at a distance such as at infinity in comparison tothe first portion (e.g., for distance power or labeled power of about +6to −18 D). This allows a more defined focus for distance (possibly asmaller spot at the distance plane for distance objects), yet stillprovides the extended depth of field provided by the first portion 701.Thus, the second portion 702 can increase the responsivity distancevision quality, creating an improvement in focusing objects at adistance. This improved distance vision can be perceived by a patient asan increase in brain-favored “positive” metrics, e.g., contrastsensitivity (CS).

In addition, as the first portion 701 is configured to provide anextended depth of field, it can supply near-equal visual acuity orvision, or at least more than the second portion 702, throughout a rangeof focus (or for a range of object distances). The spot size, wavefrontof the lens, and quality (e.g., as measured by a figure of merit such asMTF or CS) at distance, intermediate, and near points are substantiallysimilar. However, this attribute can create difficulties in evaluatingthe power of the lens using standard metrology. Post-operative clinicalevaluation of a patient using classical Gaussian metrology methods canalso be challenging. Any number of focal points could be labeled andfound to be a valid base power (e.g., distance or label power). Incertain embodiments, the second portion 702 directing a ring of marginalrays to a distance focus location can provide a repeatable measurementmore closely corresponding to distance power. Likewise, the secondportion 702 can provide a benefit in determination of the classical basepower of the implanted or un-implanted lens, and can assist in theability to accurately measure the power of the lens using industrystandard metrology methods. Thus, certain embodiments described hereincan allow for standardized measurement of a lens with extended depth offield, including, but not limited to, negative-powered,positive-powered, toric, or any combination therein.

In various embodiments described herein, the first portion 701 can allowfor the usage of different orders of spherical aberration and of aconic, biconic, or biaspheric base curve in order to balance the entirewavefront at each of its points near the exit pupil of the implantedeye, and the second portion 702 can allow for enhanced distance visionand/or monofocal distance focusing and for use of standard metrology.

In various embodiments, the anterior surface and/or posterior surface ofthe optic 700 can include other portions. For example, the anteriorsurface and/or the posterior surface of the optic 700 can furtherinclude a transition portion (not shown) providing a smooth transitionwithout discontinuity between the first portion 701 and the secondportion 702. The transition portion can also allow for additionalwavefront optimization. In some embodiments, the transition portion canhave a width (e.g., distance between the inner radii and the outerradii) in the range of about 0 to 1 mm (e.g., 0 mm, 0.1 mm, 0.2 mm, 0.3mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, or anyranges between any of these sizes). Values outside these ranges are alsopossible. In some instances, the transition between the curvatures ofthe first portion 701 and the second portion 702 can be smooth enoughthat no transition region is desired.

FIGS. 8A-8B are schematics for another example anterior surface and/or aposterior surface of an optic having a first portion configured toprovide extended depth of field, and a second portion configured toprovide enhanced distance visual acuity. In this example, the anteriorsurface and/or the posterior surface of the optic 700 can include afirst portion 701 and a second portion 702 as in FIGS. 7A-7B. As shownin FIGS. 8A-8B, the anterior surface and/or the posterior surface of theoptic 700 also can include a third portion 703 surrounding the secondportion 702. In some such embodiments, the first portion 701 can have amaximum cross-sectional diameter in the range of about 2.5-4.5 mm (e.g.,2.5 mm, 2.75 mm, 3.0 mm, 3.25 mm, 3.5 mm, 3.75 mm, 4.0 mm, 4.25 mm, 4.5mm, or any ranges between any of these sizes). The second portion 702can be described as an annulus having a width between the inner andouter radii in the range of about 0.25-1.5 mm (e.g., 0.25 mm, 0.5 mm,0.75 mm, 1.0 mm, 1.25 mm, 1.5 mm, or any ranges between any of thesesizes). Furthermore, the third portion 703 can extend from the secondportion 702 to the end of the optic 700. Accordingly, in some examples,the width of the third portion 703 can be the distance between the outerperiphery of the second portion 702 to the edge of the optic 700. Forexample, the third portion 703 can have a width (e.g., distance betweeninner and outer radii) in the range of about 0.5-3.5 mm (e.g., 0.5 mm,0.75 mm, 1.0 mm, 1.25 mm, 1.5 mm, 1.75 mm, 2.0 mm, 2.25 mm, 2.5 mm, 2.75mm, 3.0 mm, 3.5 mm, or any ranges between any of these sizes). Valuesoutside these ranges are also possible.

FIG. 8B illustrates how rays passing through the second portion 702 arefocused on the distance vision focus (labeled as 0). In contrast, rayspassing through the first portion 701 and third portion 703 focuscontinuously through the far (0), intermediate (1), and near (2) focithereby providing an extended depth of field. As discussed above, therays passing through the first portion 701 and third portion 703 form acaustic having nearly constant cross-section or beam diameter at the far(0), intermediate (1), and near (2) planes. This beam diameter, however,may potentially be larger than the size of the focus spot at the farimage plane (0) formed by the rays propagating solely through of thesecond portion 702.

The third portion 703 can have a different surface profile than thesecond profile 702. For example, the third portion 703 can have higherspherical aberration control that provides extended depth of field thanthe second portion 702. In some examples, the third portion 703 can havea shape that comprises a conic, biconic, or biaspheric envelope offsetby perturbations comprising an aspheric higher order function of radialdistance from the optical axis.

In some embodiments, the third portion 703 can have a similar surfaceprofile and/or substantially the same spherical aberration control asthe first portion 701. For example, the third portion 703 can havesubstantially the same conic, biconic, or biaspheric envelope offset byperturbations with respect to the envelope comprising an aspheric higherorder function of radial distance from the optical axis as the firstportion.

As described herein, the first portion 701 and/or the third portion 703can have a shape that comprises a conic, biconic, biaspheric envelopeoffset by perturbations comprising an aspheric higher order function ofradial distance from the optical axis. In various embodiments, theaspheric higher order function can include at least one even order term,a_(2n)r^(2n), where n is an integer and a_(2n) is a coefficient and r isthe radial distance from the optical axis. For example, the aspherichigher order function can include a second order term, a₂r², where a₂ isa coefficient and r is the radial distance from the optical axis. Theaspheric higher order function can include a fourth order term, a₄r⁴,where a₄ is a coefficient and r is the radial distance from the opticalaxis. The aspheric higher order function can also include a sixth orderterm, a₆r⁶ where a₆ is a coefficient and r is the radial distance fromthe optical axis. The aspheric higher order function can further includean eighth order term, a₈r⁸ where a₈ is a coefficient and r is the radialdistance from the optical axis. The aspheric higher order function caninclude any combination of these higher order terms and possibly moreterms.

In various embodiments, the anterior surface and/or the posteriorsurface of the optic 700 can further include a transition portion (notshown) providing a smooth transition without discontinuity between thesecond portion 702 and the third portion 703. The transition portion canalso allow for additional wavefront optimization. In some embodiments,the transition portion can have a width (e.g., distance between theinner radii and the outer radii) in the range of about 0 to 1 mm (e.g.,0 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm,0.9 mm, 1.0 mm, or any ranges between any of these sizes). Dimensionsoutside these ranges are also possible. In some instances, thetransition between the curvatures of the second portion 702 and thethird portion 703 can be smooth enough that no transition region isdesired.

In some embodiments, the caustic of the second portion 702 can besculpted to blend smoothly (or to provide a smoother transition) withthe caustic of the first portion 701 and/or the caustic of the thirdportion 703. For example, as shown in FIG. 8B, the lower causticenvelope of the second portion 702 may not blend smoothly with the lowercaustic envelope of the third portion 703 (e.g., see the discontinuitynear the intersection of the caustics). Accordingly, in someembodiments, to provide a smoother caustic transition, the conicconstant of the conic, biconic, or biaspheric envelope of the secondportion 702 may be such to blend smoother with the caustic of the firstportion 701 and/or the caustic of the third portion 703 (e.g., to fitmore tightly with the ray envelope of the first portion 701 and/or tofit more tightly with the ray envelope of the third portion 703). Forexample, in some embodiments, the second portion 702 can have a conicconstant such that the caustic of the second portion 702 blends smoothlywith the caustic of the first portion 701, for example, more smoothlythan if the second portion comprises a spherical surface. Furthermore,in some embodiments, the second portion 702 can have a conic constantsuch that the caustic of the second portion 702 blends smoothly with thecaustic of the third portion 703, for example, more smoothly than if thesecond portion comprises a spherical surface. By having a smoothercaustic transition, a slight misalignment in the surgical placement ofthe implants may be expected to produce a less noticeable effect on apatient's vision. In addition, with a smoother caustic transition,superimposed ghosting may potentially be reduced.

The various disclosures with respect to the optic 201 described hereincan also apply to the various embodiments of FIGS. 7A-8B. For example,certain embodiments of FIGS. 7A-8B can be used for phakic orpseudophakic lens implants as described herein. In embodiments used forphakic lens implants, the optic 700 can have a thickness along theoptical axis that is about 100-700 micrometers, about 100 to about 600micrometers, about 100 to about 500 micrometers, about 100 to about 400micrometers, about 100 to about 300 micrometers, or about 100 to about200 micrometers (e.g., 100 micrometers, 200 micrometers, 300micrometers, 400 micrometers, 500 micrometers, 600 micrometers, 700micrometers, any value in between such ranges, or any range formed bysuch values). In embodiments for pseudophakic lens implants, thethickness along the optical axis can be about 700 micrometers to about 4mm, about 700 micrometers to about 3 mm, about 700 micrometers to about2 mm, about 700 micrometers to about 1 mm, any value in between suchranges, or any range formed by any values in these ranges. As anotherexample, various embodiments of FIGS. 7A-8B can be used in a lenscomprising at least one haptic disposed with respect to the optic 700 toaffix the optic 700 in the eye when implanted therein. Furthermore, insome instances, the first portion 701 can be on the anterior surface ofthe optic, and the second portion 702 can be on the posterior surface ofthe optic. Likewise, in some instances, the first portion 701 can be onthe posterior surface of the optic, and the second portion 702 can be onthe anterior surface of the optic.

The terms “about” and “substantially” as used herein represent an amountequal to or close to the stated amount (e.g., an amount that stillperforms a desired function or achieves a desired result). For example,unless otherwise stated, the terms “about” and “substantially” may referto an amount that is within (e.g., above or below) 10% of, within (e.g.,above or below) 5% of, within (e.g., above or below) 1% of, within(e.g., above or below) 0.1% of, or within (e.g., above or below) 0.01%of the stated amount.

Various embodiments of the present invention have been described herein.Although this invention has been described with reference to thesespecific embodiments, the descriptions are intended to be illustrativeof the invention and are not intended to be limiting. Variousmodifications and applications may occur to those skilled in the artwithout departing from the true spirit and scope of the invention.

What is claimed is:
 1. A first lens and a second lens, together defininga lens pair, configured for implantation into a first eye and a secondeye, respectively, of a subject to provide modified monovision,comprising: the first lens configured to have positive depth of field,the first lens comprising: an optic comprising transparent material, theoptic of the first lens having an anterior surface and a posteriorsurface, the anterior surface comprising an aspheric surface, whereinthe anterior and posterior surfaces of said first lens are shaped toprovide average modulation transfer function (MTF) values that arebetween 0.1 and 0.4 at 100 lines per millimeter for at least 90% of theobject vergences within the range of 0 to 2.0 D or 0 to 2.5 D when saidoptic of said first lens is inserted into a model eye having an aperturesize from 4 to 6 millimeters, wherein said average MTF values of saidfirst lens comprise MTF values at 100 lines per millimeter integratedover the wavelengths between about 400 to 700 nm weighted by thephotopic luminosity function for on axis objects, and the second lensconfigured to have negative depth of field, the second lens comprising:an optic comprising transparent material, said optic of said second lenshaving an anterior surface and a posterior surface, said anteriorsurface comprising an aspheric surface, wherein the anterior andposterior surfaces of said second lens are shaped to provide averagemodulation transfer function (MTF) values that are between 0.1 and 0.4at 100 lines per millimeter for at least 90% of the object vergenceswithin the range of −2.0 to 0 D or −2.5 to 0 D when said optic of saidsecond lens is inserted into the model eye having an aperture size from4 to 6 millimeters, wherein said average MTF values of said second lenscomprise MTF values at 100 lines per millimeter integrated over thewavelengths between about 400 to 700 nm weighted by the photopicluminosity function for on axis objects, such that when the first andsecond lenses are implanted in a first eye and a second eye,respectively, of a subject, the positive depth of field of the firstlens provides the subject an extended depth of field in the direction ofnearer objects, and the negative depth of field of the second lensprovides the subject an extended depth of field in the direction of moredistant objects.
 2. The lens pair of claim 1, wherein the aggregatedepth of field provided by the first and second lenses is greater thanthe depth of field provided by the first lens or the second lens alone.3. The lens pair of claim 1, wherein the model eye is selected from thegroups consisting of a Liou-Brennan model eye, a Badal model eye, anArizona model eye, and an Indiana model eye.
 4. The lens pair of claim1, wherein said modulation transfer function values of the first lens orthe second lens are provided when said optic of the first lens or thesecond lens is inserted in the model eye in a phakic configuration. 5.The lens pair of claim 1, wherein the modulation transfer functionvalues of the first lens or the second lens are provided when the opticof the first lens or the second lens is inserted in the model eye in anaphakic configuration.
 6. The lens pair of claim 1, wherein one or moreof the first lens and the second lens comprises haptic portions.
 7. Thelens pair of claim 1, wherein the optic of the first lens or the secondlens has an optical axis and a thickness through the optical axis thatis between about 100-700 microns.
 8. The lens pair of claim 1, whereinthe optic of the first lens or the second lens has an optical axis and athickness through the optical axis that is between about 700 microns and4 millimeters.
 9. The lens pair of claim 8, wherein the optic of thefirst lens or the second lens has a thickness along the optical axisthat is between about 700 microns and 2 millimeters.
 10. The lens pairof claim 1, wherein the aperture size is 6 millimeters.
 11. The lenspair of claim 1, wherein the aperture size is 4 millimeters.
 12. Thelens pair of claim 1, wherein the anterior and posterior surfaces of thefirst lens are shaped to provide average modulation transfer function(MTF) values that are between 0.1 and 0.4 at 100 lines per millimeterfor at least 95% of the object vergences within the range of 0 to 2.0 Dor 0 to 2.5 D.
 13. The lens pair of claim 1, wherein the anterior andposterior surfaces of the second lens are shaped to provide averagemodulation transfer function (MTF) values that are between 0.1 and 0.4at 100 lines per millimeter for at least 95% of the object vergenceswithin the range of −2.0 to 0 D or −2.5 to 0 D.
 14. The lens pair ofclaim 1, wherein the anterior and posterior surfaces of the first lensare shaped to provide modulation transfer functions (MTF) without phasereversal for at least 90% of the object vergences within the range of 0to 2.0 D or 0 to 2.5 D when said optic is inserted into the model eyehaving an aperture size from 4 to 6 millimeters.
 15. The lens pair ofclaim 14, wherein the anterior and posterior surfaces of said first lensare shaped to provide modulation transfer functions (MTF) without phasereversal for at least 95% of the object vergences within the range of 0to 2.0 D or 0 to 2.5 D when said optic is inserted into the model eyehaving an aperture size of 4 from 6 millimeters.
 16. The lens pair ofclaim 1, wherein the anterior and posterior surfaces of the second lensare shaped to provide modulation transfer functions (MTF) without phasereversal for at least 90% of the object vergences within the range of−2.0 to 0 D or −2.5 to 0 D when said optic is inserted into the modeleye having an aperture size from 4 to 6 millimeters.
 17. The lens pairof claim 16, wherein anterior and posterior surfaces of said second lensare shaped to provide modulation transfer functions (MTF) without phasereversal for at least 95% of the object vergences within the range of−2.0 to 0 D or −2.5 to 0 D when said optic is inserted into the modeleye having an aperture size from 4 to 6 millimeters.
 18. The lens pairof claim 1, wherein the first lens is adapted to be implanted in thesubject's dominant eye, and the second lens is adapted to be implantedin the subject's non-dominant eye.
 19. The lens pair of claim 1, whereinthe first lens is configured to correct distance vision, and the secondlens is configured to correct near vision.
 20. A method of providingmodified monovision to a subject with a first lens and a second lens,comprising: implanting the first lens into a first eye of the subject,the first lens configured with positive extended depth of field; andimplanting the second lens into a second eye of the subject, the secondlens configured with negative extended depth of field, the second eyedifferent than the first eye, wherein implanting the first lens with thepositive extended depth of field provides the subject an extended depthof field in the direction of nearer objects, and wherein implanting thesecond lens with the negative extended depth of field provides thesubject an extended depth of field in the direction of more distantobjects.
 21. The method of claim 20, wherein the aggregate depth offield provided by the first and second lenses is greater than the depthof field provided by the first lens or the second lens alone.
 22. Themethod of claim 20, wherein the first eye is a dominant eye such thatimplanting the first lens comprises implanting the first lens in thesubject's dominant eye.
 23. The method of claim 22, wherein the secondeye is a non-dominant eye, such that implanting the second lenscomprises implanting the second lens in the subject's non-dominant eye.24. The method of claim 20, wherein the first lens is configured tocorrect distance vision.
 25. The method of claim 24, wherein the secondlens is configured to correct near vision.
 26. The method of claim 20,wherein the first lens comprises an optic comprising transparentmaterial, the optic of the first lens having an anterior surface and aposterior surface, the anterior surface comprising an aspheric surface,wherein the anterior and posterior surfaces of the first optic areshaped to provide average modulation transfer function (MTF) values thatare between 0.1 and 0.4 at 100 lines per millimeter for at least 90% ofthe object vergences within the range of 0 to 2.0 D or 0 to 2.5 D whenthe optic of the first lens is inserted into a model eye having anaperture size from 4 to 6 millimeters, wherein the average MTF values ofthe first lens comprise MTF values at 100 lines per millimeterintegrated over the wavelengths between about 400 to 700 nm weighted bythe photopic luminosity function for on axis objects.
 27. The method ofclaim 26, wherein the second lens comprises an optic comprisingtransparent material, the optic of the second lens having an anteriorsurface and a posterior surface, the anterior surface comprising anaspheric surface, wherein the anterior and posterior surfaces of thesecond optic are shaped to provide average modulation transfer function(MTF) values that are between 0.1 and 0.4 at 100 lines per millimeterfor at least 90% of the object vergences within the range of −2.0 to 0 Dor −2.5 to 0 D when the optic of the second lens is inserted into amodel eye having an aperture size from 4 to 6 millimeters, wherein theaverage MTF values of the second lens comprise MTF values at 100 linesper millimeter integrated over the wavelengths between about 400 to 700nm weighted by the photopic luminosity function for on axis objects.